Centrifugal electrical switch



A0 27, 1940, c c. STEEL CENTRIFUGAL ELECTRICAL SWITCH FiI March 51, 1939 2 Sheets-Sheet l I N VEN TOR.

g- 1940- c. c. STEEL CENTRIFUGAL ELECTRICAL SWITCH 2 Sheets-Sheet 2 WEE- Filed March 31, 15339 INVENTOR.

RNEY

a M W M Patented Aug. 27, 1940 UNITED STATES i A'l'ENT GFFICE 8 Claims.

This invention relates to a speed control means for motor vehicles and more particularly to a means for controlling the engine speed thereof, and it consists in the constructions, arrangements and combinations herein described and claimed.

It is an object to provide a switch of the kind described in which the switch actuates an elector-magnetic valve for control of gaseous fuel to the engine, in a manner as disclosed in my pending application filed July 7, 1938, Serial No. 217,985.

It is also an object of the invention to provide a centrifugal switch of extreme simplicity, of

; sturdy construction and which may be operatively mounted upon either of numerous driven shafts, associated with an engine, such as the generator shaft, fan shaft, distributer shaft, etc.

It is a still further object of the invention to provide a centrifugal switch which may be readily adjusted to a desiredspeed and sealed against tampering.

It is also an object of the invention to provide a novel construction of rotor contact, in which the movable contact is positively and smoothly uided into engagement with a contact ring, thereby eliminating liability of a fluctuation of current to the valve or other means to be controlled.

Additional objects, advantages and features of invention will be apparent from the following description considered. in conjunction with the accompanying drawings, wherein Figure l is a front elevation of the switch.

Figure 2 is a vertical cross section thereof, the

closure screw having been removed.

Figure 3 is a side elevation of the switch partly in section.

Figure 4 is a side elevation of a generator, partly in section, illustrating the switch installed upon the shaft thereof.

Figure 5 is a perspective view of an adapter sleeve employed in the installation.

Fgure 6 is a plan view of the rotor partly in section.

Figure '7 is a cross section through a modified form of switch.

Figure 8 is an elevation thereof, illustrating the manner of adjusting the setting of the switch, part of the adjusting ring segment being broken away.

Figure 9 is an elevation partly in section, illustrating a modified form of rotor illustrated in Figure 6.

Figure 10 is a further modification of the rotor.

Attention is first invited to Figures 1 to 6 of the drawings, wherein I have illustrated a casing H] of annular formation, having a back wall I! and an annular flange l2 formed integrally with the wall ii. The wall H has axial hub 13 extended outwardly therefrom internally threaded as at 5 M5, for a purpose to be explained.

The wall l i has an outwardly directed offset recess l5, as clearly shown in Figure 2, and within the wall it and recess Hi there is secured an insulator lining I6. 10

A binding post H is housed within the recess and projects through a suitable aperture formed therein, the latter including a wing nut l 8 for securement of a cable l9, leading to the valve or i other instrument to be controlled, these devices 15 not being shown since they form no part of the present invention. The binding post I! will be suitably insulated, as shown.

A contact ring is firmly fixed within the insulatorlining I6, and in order that a good elec- 20 trical contact is maintained between the ring 20 and the binding post ll, a helical spring 2i is positioned within the insulated recess, one end bearing upon the ring 20 while the other bears upon the head of the binding post.

The casing it is closed by a plate 22 suitably bolted to the flange l I thereof, and includes a hub portion 23 forming a support for a shaft of the rotor now to be described.

Attention is invited to Figures 2 and 6 of the drawings for an understanding of the construction of rotor. The rotor is indicated at 24 and is composed of a main section 25 and a segmental section 26, the latter being slidably related to the main section under action of centrifugal force, as will be understood as the description proceeds. The main section 25 is press-fitted to a shaft 2'! so that the section and shaft rotate in unison, the shaft being suitably journalled in the hubs l3 and 23. I

The section 25 is provided with a straight planiform face 28 complemental to a similar face 29 of the section 26 and when in abutting relation the two sections 25-45 form a true annular rotor. In order that the section 26 may be properly guided during movements, the section 25 has a pair of spaced pins 39 complemental to respective bores 3! formed in the section 25. The pins 3?! have a sliding fit within the bores 3!, but sulficiently snug so as to tend to compress air in the bores, thereby lessening any sudden seating of the section 26 upon the section 25. Obviously, however, any air in the bores will eventually seep past the pins and will not interfere with proper seating of the section 26.

v the section 25, and the section'25 is provided with an internally threaded bore 34, all of which is clearly shown in Figure 2.

A bolt 35 is extended through the aligned bores 32 and 33 and is threadedly engaged in the bore 34. A helical steel spring 36 encircles the bolt, being interposed between the base 31 of the bore 33 and the head of the bolt 35, the latter being provided with a slot for actuating the bolt for varyingthe tension of the spring 35. It will be apparent that by varying the tension of the spring the time at which the segment 26 functions to complete a contact with the ring 20 will be varied,

and this means provides for adjustment of the switch to desired speeds. In order that the bolt 35 may be locked against movement, a set screw 35" is provided in the segment 25 and impinges upon the bolt (see Fig. 6).

, The casing ill, liner I5, and ring 20 are provided with an aperture 38 aligned with the bore 33 for the purpose of gaining access to the bolt 35 from exteriorly of the casing, which would be required when adjusting the tension of the spring to a desired speed, which of course would be accomplished at the time of assembly.

The aperture 38 of the casing is closed by a threaded plug 39, as shown in Figures 1, 3 and 4, the latter being drilled for passage of a sealing wire M1, the loop of which is passed through a wing of the nut l8, the free ends of the wire being sealed by a customary seal 40. Thus tampering with adjustment of the spring is forestalled.

' The assembled switch may be incorporated upon a shaft in Various manners, but in Figure 4, I have illustrated a preferred connection with the shaft of a generator of a motor vehicle, the generator, as is generally understood, being driven by the engine of the vehicle.

The generator is indicated at 4|, and includes a shaft 52 the free end of which is drilled and tapped to receive an externally threaded adapter sleeve 43, the latter having a square bore 44 complemental to the shaft 21 of the rotor.

The housing plate 45 of the generator is apertured in line with the adapter sleeve 43 to re ceive a headed bushing 46, the latter being externally threaded to'receive a lock washer 41 and nut 48. The bushing may thus be securely locked to the plate 45. ,The bushing 46 is of a substantial length so that the hub l3 may be screwed thereupon. If desired, the switch may include a bracket 69 comprising a bearing 55 circumscribing the hub l3, from which arms 5| are extended, apertured so as to be secured by bolts of the plate 55.

The operation of the switch will be readily understood from the following description. With a given switch, set to operate, we will say at a speed of 50- miles per hour when the engine of the vehiclehas attained the revolutions per minute required to attain such speed, the segment 26 will be moved outwardly by centrifugal force to a point of contact with the ring 25. When such contact occurs the electro-magnet valve or other device (not shown) will be energized to cut off the supply of fuel to the engine. However, this action does not immediately stop the engine of =1". the vehicle, since there is ample gasoline in the bowl of thecarburetor and the fuel line thereto to permit continued operation of the engine, for a short period of time,thereby avoiding a hazard in passing a vehicle. As soon as the engine of the vehicle is brought to a point below the speed set, the spring 36 will draw the segment 26 from contact with the ring 20, the electro-magnetic valve will be de-energized, and fuel will again pass to the carburetor.

In Figure 6, a slightly modified form of rotor is shown differing from that thus far described, in that carbon contacts 52 are fixed to the segment 25, so that a carbon to metal contact is provided rather than metal contact.

In Figures 7 and 8 a modified form of switch is illustrated, in which a casing II] is provided, as before, including a closure plate 22 Within the casing Ill a contact ring 53 is fixed, insulated from the casing by a liner 54.

The annular wall 55 of the casing is provided at diametrically opposite sides with inclined slots 56, one of which is shown in Figure 8. Through one of these-slots the insulated shank 51 of a binding post 58 is extended, the inner end of the post being electrically connected with the ring 53. Through the slot 56 at the other side of the casing, the insulated shank 59 of a lock bolt is extended, the inner end being threadedly engaged with the ring 53.

The slots 55 extend diagonally of the circumference of the casing and obviously, by loosening the binding post nut 55 and the lock nut 6| the ring 53 may be rotated, which will simultaneously move the ring axially of the casing. A cover plate 62-may be employed to exclude dust and foreign matter from the interior of the casing. Theinterior of the ring 53 is of tapered formation, coinciding with the taper of the periphery of a rotor 63, and it will therefore be apparent that the spacing between the tapered face of the ring and the rotor may be varied by rotative movement of the ring, since the slots 56 and insulated shanks 5I--59 will either advance the ring toward or away from the rotor, and through these means a variable setting of the switch is attained.

The rotor 63 includes a segment 64 fixed to a shaft 55 and a segment 55 complemental to the first segment to define an annular rotor. The segments will include guide pins 67 similar to the first form described.

Each of the segments 54 and 56 has a groove 68 circumscribing its outer peripheries, for seating engagement of a helical spring 69, the latter holding the segment 66 in normal inoperative position, but yieldable to permit the segment to contact the ring. 53 at a predetermined speed.

- In Figure 9 the movable segment 19 is held in inoperative position by a steel C-spring, the

spring being seated in a groove H below the periphery of the segments.

In Figure 10, the rotor 12 comprises a segment 13 hingedly connected at one end to the rotor 12, asindicated at M. A short helical spring 75 is fixed at one end to the free end of the segment, while the other end of the spring is secured to the rotor l2. The spring 15 will occupy a groove 76 so as to avoid protrudence beyond the periphery of the rotor and segment.

While I have shown and described preferred forms of my switch, this is by way of illustration only, and I consider as my own, all such modifications in structure as fairly fall within the scope of the appended claims.

I claim:

1. A centrifugalelectrical switch comprising a casing, an annular contact ring within the casing insulated therefrom, a revoluble shaft within the casing having means for establishing driving connections with a driven shaft, a rotor on the shaft, the rotor having a straight planiform face, a segmental contact complemental to the planiform face of the rotor, a pair ofspaced bores in the rotor, guide pins on the segmental contact slidably engaged in respective bores, and having a fit to partially compress air upon inward movement of the segmental contact, and spring means for limiting outward sliding movement of the segmental contact.

2. The structure of claim 1 in which the segmental contact comprises carbon contact elements.

3. A centrifugal electrical switch comprising a casing, an annular contact ring within the casing insulated therefrom, a revoluble shaft within the casing having means for establishing driving connections with a driven shaft, a rotor on the shaft, the rotor having a straight planiform face, a segmental contact complemental to the planiform face of the rotor, a pair of spaced bores in the rotor, guide pins on the segmental contact slidably engaged in respective boxes, and having a fit to partially compress air upon inward movement of the segmental contact, said rotor and shaft having aligned bores, said segmental contact having a threaded bore aligned with bores of the rotor and shaft, a threaded bolt extended through the first named bores and threadedly engaged with the threaded bore, and spring means cooperable with the bolt for maintaining the segmental contact in normal position.

4. A centrifugal electrical switch comprising a casing, an annular contact ring within the casing insulated therefrom, a revoluble shaft within the casing having means for establishing driving connections with the driven shaft, a rotor on the shaft having a straight planiform face, a segmental contact complemental to the planiform face of the rotor, a pair of spaced bores in the rotor, guide pins on the segmental contact slidably engaged in respective bores, and having a fit to partially compress air upon inward movement of the segmental contact, said rotor and shaft having aligned bores, said segmental contact having a threaded bore aligned with bores of the rotor and shaft, a threaded bolt extended through the first named bores and threadedly engaged with the threaded bore, a helical spring interposed between the head of the bolt and the reduced base of the bore of the rotor, and said segmental contact having carbon contact portions on its periphery.

5. A rotor for centrifugal switches comprising a rotor having a shaft, said rotor and shaft having aligned bores, said rotor having a planiform face extending at right angles to the shaft, a segmental contact complemental to the planiform face and defining a true annular member, a pair of pins on the segmental contact slidably engaged in respective bores and having a fit to partially compress air upon inward movement of the pins, said segmental contact having a threaded bore, a threaded bolt extended through the first named bores and threadedly engaged in the threaded bore of the segmental contact, a helical spring interposed between the head of the bolt and the base of the bore of the rotor and said last named bore opening upon the periphery of the rotor whereby said bolt may be actuated to vary the tension of the spring.

6. The structure of claim 5 in which the segmental contact comprises carbon contacts on its periphery.

'l. The structure of claim 5 in which the segmental contact comprises carbon contacts on its periphery and further comprises a set screw for locking the bolt in an adjusted position;

8. A centrifugal electrical switch comprising a casing having an offset recess, an insulator lining within the casing and recess, an annular contact ring seated against the lining, a binding post housed within the lining of the recess, spring means between the binding post and the contact ring; a revoluble shaft within the casing having means for establishing driving connections with a driven shaft, a rotor on the shaft, the rotor having a straight planiform face, a contact segment complemental to the planiform face of the rotor, a pair of spaced bores in the rotor, guide pins on the segmental contact slidably engaged in respective bores, and having a fit to partially compress air in the bores upon inward movement of the segment and pins; said rotor and shaft having aligned bores, said segmental contact having a threaded bore aligned with the first named bores, a threaded bolt extended through the first named bores and threadedly engaged in the threaded bore of the segmental contact, a helical spring interposed between the head of the bolt and the base of the bore of the rotor, said last named bore opening upon the periphery of the rotor, means for locking the bolt in an adjusted position, and said casing having a removable closure plug, the opening for reception thereof being aligned for engagement of said bolt in one position of its rotation, whereby to vary the tension of the spring.

CHARLES C. STEEL. 

